This is a unit in 7-8 sessions about objects outside of our solar system, including galaxies and the universe. Learners will investigate the contents of the universe, why light years are used to measure distances in space, the lifespan of a star,...(View More) and detecting extrasolar planets. Finally, they will examine evidence for habitable worlds beyond earth. This is Unit 4 of the GEMS Space Science Sequence for Grades 6-8, which is available for purchase (see related link).(View Less)